WO2016136601A1

WO2016136601A1 - Cylindrical product made of fiber-reinforced resin material, injection molding die therefor, and injection molding method

Info

Publication number: WO2016136601A1
Application number: PCT/JP2016/054797
Authority: WO
Inventors: 健二朗瀧
Original assignee: 株式会社エンプラス
Priority date: 2015-02-23
Filing date: 2016-02-19
Publication date: 2016-09-01
Also published as: CN107249848A; JP6512858B2; US10300641B2; US20180029261A1; CN107249848B; JP2016155225A

Abstract

[Problem] To improve the strength of the portion of a cylindrical product, which is made of a fiber-reinforced resin material, in which a weld line is formed. [Solution] An injection molding die 2 is configured so that by injecting reinforcing fiber-containing molten resin from a gate 13 into a cavity 7 formed between an outer piece 3 and a center pin 4, the reinforcing fiber-containing molten resin merges inside the cavity 7 to form a weld line in the reinforcing fiber-containing molten resin inside the cavity 7. By moving the outer piece 3 with respect to the center pin 4 in said injection molding die 2, the distance to the center pin 4 is changed and the reinforcing fiber-containing molten resin inside the cavity 7 is forced to flow, disrupting the orientation of the reinforcing fibers in the weld line. As a result, the reinforcing fibers in the weld line and near the weld line in the cylindrical product 1 are intertwined, improving the strength of the portion of the cylindrical product 1 in which the weld line is formed.

Description

Cylindrical product made of fiber reinforced resin material, injection molding die thereof, and injection molding method

The present invention relates to a fiber reinforced resin material cylindrical product that improves the strength of a portion where a weld line generated by injection molding is formed, an injection mold thereof, and an injection molding method.

Conventionally, as shown in FIG. 13, a molten resin is injected into a cavity 1002 of a mold 1001 from a pinpoint gate 1000 to produce a cylindrical product 1003 (see FIG. 14) in which the shape of the cavity 1002 is transferred. A molding method is known (see Patent Document 1).

Japanese Patent No. 3383971

However, as shown in FIGS. 13 and 14, in the conventional injection molding method, when the molten resin is injected from the pinpoint gate 1000 into the cavity 1002 of the mold 1001, the portion where the molten resin merges in the cavity 1002. It has been pointed out that a weld line 1004 is formed, and that the weld line 1004 reduces the strength of the tubular product 1003. In particular, the cylindrical product 1003 injection-molded using a fiber reinforced resin material has the reinforcing fibers 1005 of the weld line 1004 aligned in one direction (the direction in which the molten resin flows) (see FIG. 15), so When press-fitted, there is a problem that cracks are likely to occur in the portion where the weld line 1004 is formed.

Therefore, an object of the present invention is to provide a cylindrical product made of a fiber reinforced resin material in which the strength of a portion where a weld line is formed, an injection mold thereof, and an injection molding method.

In the present invention, molten resin containing reinforcing fibers is injected into the

cavities

7 and 105 from the

gates

13 and 111, so that the molten resin containing reinforcing fibers merges in the

cavities

7 and 105 to form the weld line 34. The present invention relates to an injection mold 2 for a tubular product 1 to be manufactured. In the present invention, the

cavities

7 and 105 are provided between a

center pin

4 and 150 forming the inner peripheral surface side of the tubular product 1 and an

outer piece

3 and 151 forming the outer peripheral surface side of the tubular product 1. Is formed. Further, the

outer piece

3, 151 is moved with respect to the

center pin

4, 150, thereby changing the distance from the

center pin

4, 150 and containing the reinforcing fibers in the

cavities

7, 105. The molten resin is forced to flow, and the direction of the reinforcing fibers in the weld line 34 is disturbed.

Further, according to the present invention, the molten resin containing the reinforcing fibers is injected into the

cavities

7 and 105 from the

gates

13 and 111 into the

cavities

7 and 105, so that the molten resin containing the reinforcing fibers merges in the

cavities

7 and 105. The present invention relates to a method for injection molding of a cylindrical product 1 in which is formed. In the present invention, the

cavities

7 and 105 are provided between a

center pin

outer piece

3 and 151 forming the outer peripheral surface side of the tubular product 1. Is formed. Then, by moving the

outer piece

3, 151 with respect to the

center pin

4, 150, the distance from the

center pin

4, 150 is changed, and the molten resin containing the reinforcing fibers in the

cavities

7, 105 is obtained. Is forced to flow, and the direction of the reinforcing fibers in the weld line 34 is disturbed.

Further, according to the present invention, molten resin containing reinforcing fibers is injected into the

cavities

7 and 105 from the

gates

13 and 111, and the molten resin containing reinforcing fibers merges in the

cavities

7 and 105 to form a weld line 34. This relates to a tubular product 1 made of fiber-reinforced resin material. In the tubular product 1 made of fiber reinforced resin material according to the present invention, the

cavities

7 and 105 form the

center pins

4 and 150 that form the inner peripheral surface side of the tubular product 1 and the outer peripheral surface side of the tubular product 1. The space between the

outer pins

3 and 151 is changed, and the

outer pins

3 and 151 are moved with respect to the

center pins

4 and 150, whereby the distance from the

center pins

4 and 150 is changed. 7 and 105, the molten resin containing the reinforcing fibers is forced to flow, and the direction of the reinforcing fibers in the weld line 34 is disturbed.

According to the present invention, the direction of the weld line in the injection-molded cylindrical product and the reinforcing fiber in the vicinity of the weld line is disturbed, and the weld line in the cylindrical product and the reinforcing fiber in the vicinity of the weld line are intertwined. The weld line becomes inconspicuous and the strength of the portion of the tubular product where the weld line is formed is improved.

It is a figure which shows the structure of the injection mold which concerns on 1st Embodiment of this invention, and is a figure which shows the structure of the injection mold in an injection standby state. It is a figure which shows the structure of the injection mold which concerns on 1st Embodiment of this invention, and is the case where the outer piece in an injection waiting state is eccentrically rotated only a predetermined angle ((theta)) clockwise with respect to the center pin. It is a figure which shows the structure of an injection mold. It is a figure which shows typically the relationship between a center pin and an outer piece. It is a figure which shows the cylindrical goods injection-molded with the injection mold which concerns on 1st Embodiment of this invention. 4 (a) is a front view of the tubular product, FIG. 4 (b) is a side view of the tubular product, and FIG. 4 (c) is cut along line A5-A5 in FIG. 4 (a). It is sectional drawing of the cylindrical goods shown. It is a figure which shows the structure of the injection mold which concerns on 2nd Embodiment of this invention, and is a figure which shows the modification of the rotation drive means of the injection mold shown in FIG. It is a figure which shows the structure of the injection mold which concerns on 2nd Embodiment of this invention, and is a case where the outer piece in the injection standby state of FIG. 5 is eccentrically rotated by a predetermined angle clockwise with respect to the center pin. It is a figure which shows the structure of an injection mold. It is a figure which shows the structure of the injection mold which concerns on 3rd Embodiment of this invention, and is a figure which shows the modification of the injection mold shown in FIG. It is a figure which shows the structure of the injection-molding die concerning 3rd Embodiment of this invention, and is the case where the outer piece in the injection standby state of FIG. 7 is eccentrically rotated by a predetermined angle clockwise with respect to the center pin. FIG. 3 is a view showing the structure of an injection mold 2. It is a figure which shows the cylindrical goods injection-molded with the injection mold which concerns on 3rd Embodiment of this invention. 9A is a front view of the cylindrical product, FIG. 9B is a side view of the cylindrical product, and FIG. 9C is cut along line A14-A14 in FIG. 9A. It is sectional drawing of the cylindrical goods shown. It is a figure which shows the structure of the injection mold which concerns on 4th Embodiment of this invention, and is a figure which shows the modification of the rotation drive means of the injection mold shown in FIG. It is a figure which shows the structure of the injection mold which concerns on 4th Embodiment of this invention, and is the case where the outer piece in the injection standby state of FIG. 10 is eccentrically rotated only a predetermined angle clockwise with respect to the center pin. It is a figure which shows the structure of an injection mold. It is a figure which shows the injection mold which concerns on 5th Embodiment of this invention. It is a figure which shows the structure of the injection molding metal mold | die of the cylindrical goods which concerns on a prior art example. It is an external appearance perspective view of the cylindrical goods which concern on a prior art example. It is a figure which shows the orientation of the reinforcement fiber in the weld line of the cylindrical goods which concern on a prior art example, and its vicinity.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
(Cylindrical injection mold)
1 and 2 are views showing an injection mold 2 for a cylindrical product 1 according to the first embodiment of the present invention. Among these, FIG. 1 is a figure which shows the structure of the injection mold 2 in an injection standby state. FIG. 2 is a view showing the structure of the injection mold 2 when the outer piece 3 in the injection standby state is eccentrically rotated by a predetermined angle (θ) in the clockwise direction with respect to the center pin 4. FIG. 1 (a) is a plan view of a second mold shown by cutting the injection mold shown in FIG. 1 (b) along the line A1-A1. FIG. 1B is a cross-sectional view of the injection mold shown cut along the line A2-A2 in FIG. FIG. 2A is a plan view of a second mold shown by cutting the injection mold shown in FIG. 2B along the line A3-A3. FIG. 2B is a cross-sectional view of the injection mold shown cut along the line A4-A4 in FIG.

As shown in FIGS. 1 and 2, the injection mold 2 has a cavity 7 formed on the side of the butted

surfaces

5a and 6a of the first mold 5 and the second mold 6. The cavity 7 has a shape that forms a tubular product 1 made of a fiber reinforced resin material (hereinafter abbreviated as a tubular product 1) shown in FIG. 4, and is filled with a molten resin containing reinforcing fibers. Yes. As shown in FIG. 4, the tubular product 1 includes a cylindrical portion 8 and a hollow disc portion 10 integrally formed on one end side of the cylindrical portion 8. The cavity 7 that forms the cylindrical product 1 includes a first cavity portion 11 that forms the cylindrical portion 8, and a second cavity portion 12 that is positioned on one end side of the first cavity portion 11 and forms the hollow disc portion 10. ,have. The cavity 7 is formed in the second mold 6 so that the opening end is closed by the first mold 5. Note that molten resin containing reinforcing fibers are PA66-GF30 (nylon 66 containing 30% glass fiber), PA6-GF (nylon 6 containing 20% glass fiber), PPS-GF40 (polyphenylene sulfide containing 40% glass fiber), POM. -GF25 (polyacetal containing 25% glass fiber) or the like is used.

The first mold 5 is formed with a gate 13 (pinpoint gate) that opens to the second cavity 12 formed in the second mold 6. The second mold 6 includes a substantially round bar-shaped center pin 4 positioned on the inner peripheral surface side of the first cavity portion 11 and an outer piece 3 positioned on the outer peripheral surface side of the first cavity portion 11. Yes. The outer peripheral surface 14a of the large-diameter portion 14 of the center pin 4 forms the inner peripheral surface side of the first cavity portion 11, and the inner peripheral surface 3a of the outer piece 3 (the inner peripheral surface of the cavity forming hole 18) is the first cavity. The outer peripheral surface side of the part 11 is formed.

A round bar-shaped small-diameter portion 15 that is abutted against the abutting surface 5a of the first mold 5 is formed on the tip side of the center pin 4. The small diameter portion 15 is integrally formed at the center of the front end side of the center pin 4 so as to form the central hole 16 of the hollow disc portion 10. The second cavity portion 12 is formed by the distal end surface 17 of the large diameter portion 14 of the center pin 4, the outer peripheral surface 15 a of the small diameter portion 15, and the butting surface 5 a of the first mold 5.

The outer piece 3 is a cylindrical body formed so as to surround the center pin 4, and the cavity forming hole 18 that forms the outer peripheral surface side of the first cavity portion 11 is in the direction along the central axis P 0 (FIG. 1B). And in the direction along the Z-axis in FIG. The outer piece 3 has an end face 3b at one end abutted against the abutting face 5a of the first mold 5 at the time of mold clamping, and the other end is rotatably supported by the outer piece support 20. On the other end side of the outer piece 3, a flange-like flange portion 21 is formed, and an annular recess 22 having a diameter larger than that of the cavity forming hole 18 is formed. Further, the outer piece 3 is engaged so that the annular recess 22 on the other end side can be rotated relative to the eccentric rotation support portion 23 of the outer piece support 20, and the end surface 21 a of the flange portion 21 is the outer piece support 20. The outer piece support surface 20a is supported so as to be relatively rotatable, and can be rotated around the central axis P1 of the eccentric rotation support portion 23. The outer piece 3 has a center axis P0 coaxially positioned with the center axis P1 of the eccentric rotation support portion 23, whereas the center 18a of the cavity forming hole 18 has a predetermined dimension (ε) with respect to the center axis P0. ) Is eccentric (see FIG. 3). Further, the flange portion 21 of the outer piece 3 is formed with a notch groove 26 that engages with the driving protrusion 25 of the rotation driving means 24. Such an outer piece 3 is rotated around the central axis P1 of the eccentric rotation support part 23 by a predetermined angle (θ) by the rotation driving means 24 (see FIGS. 1A and 2A). . Thereby, the outer piece 3 is rotated in an eccentric state with respect to the central axis P <b> 2 of the center pin 4. Further, the outer piece 3 is housed in an outer piece housing hole 27 whose outer peripheral surface 3 c is formed in the second die 6, and the flange portion 21 is inside the flange portion containing recess 28 formed in the second die 6. Is housed in. The outer piece accommodation hole 27 and the flange portion accommodation recess 28 of the second mold 6 are formed around the central axis P2 of the center pin 4, and the outer periphery of the outer piece 3 rotated by the rotation driving means 24. It is formed so as not to contact the surface 3 c and the outer peripheral surface 21 b of the flange portion 21 of the outer piece 3.

The outer piece support body 20 has an outer piece support surface 20a formed on the tip side (the end side near the outer piece 3), and an annular eccentric rotation support portion 23 extending from the outer piece support surface 20a along the Z-axis direction. It is formed to protrude. The outer piece support surface 20a positions the outer piece 3 in the Z-axis direction. The eccentric rotation support portion 23 is fitted to the inner peripheral surface of the annular recess 22 of the outer piece 3 via a slight gap, and positions the outer piece 3 in the XY plane. In the outer piece support 20, the center axis P 1 of the eccentric rotation support portion 23 is eccentric with respect to the center axis P 2 of the center pin 4 by a predetermined dimension (ε). The central axis P1 of the eccentric rotation support portion 23 is formed so as to be coaxial with the central axis P0 of the outer piece 3. Further, the outer piece support 20 accommodates a cylindrical eject sleeve 30 that slides along the center pin 4. The eject sleeve 30 is formed after the molten resin containing the reinforcing fibers in the cavity 7 is cooled and solidified to form the tubular product 1, and the first mold 5 and the second mold 6 are separated from each other. 1 is pushed out of the cavity 7.

FIG. 3 is a diagram schematically showing the relationship between the center pin 4 and the outer piece 3. 3, the cavity 7 has a uniform cavity width (W) along the circumferential direction of the center pin 4 when the center axis P2 of the center pin 4 and the center 18a of the cavity forming hole 18 of the outer piece 3 are concentric. It corresponds to the cavity 7 shown in FIG. In this case, the cavity forming hole 18 is indicated by a solid line in FIG.

The center axis P1 of the eccentric rotation support portion 23 is disposed on a center line (reference center line) 31 that intersects the center axis P2 of the center pin 4 and extends in parallel with the Y axis. The central axis P1 of the eccentric rotation support portion 23 is located away from the central axis P2 of the center pin 4 along the reference center line 31 (eccentric). When the outer piece 3 is rotated by a predetermined angle (θ) in the counterclockwise direction around the central axis P1 of the eccentric rotation support portion 23, the center 18a of the cavity forming hole 18 becomes the center pin 4. 1 is shifted from the center (center axis P2) and placed at a position in an injection standby state (placed as shown in FIG. 1A). The cavity forming hole 18 at this time is indicated by a two-dot chain line in FIG. 3, and the center 18 a of the cavity forming hole 18 is at the position that is most greatly displaced from the center axis P <b> 2 of the center pin 4. As a result, the distance (abbreviated as cavity width (W)) between the outer peripheral surface of the center pin 4 and the inner peripheral surface of the cavity forming hole 18 along the radial direction of the center pin 4 is along the circumferential direction of the center pin 4. The center line 32 passing through the center of the center pin 4 (crossing the center axis P2) and parallel to the X axis is rotated counterclockwise (θ / 2) around the center axis P2. On the center line 33, the maximum value (Wmax) and the minimum value (Wmin) are obtained. Moreover, the cavity 7 has a line-symmetric shape with the center line 33 as the axis of symmetry. Therefore, the injection mold 2 according to the present embodiment is arranged such that the gate 13 is disposed on the side on the center line 33 and on the side where the cavity width (W) becomes the minimum value (Wmin). 7 so that the weld line 34 is formed at a position on the center line 33 (position where the cavity width (W) becomes the maximum value (Wmax)) where the molten resin injected into the fiber 7 is rotated 180 ° from the gate 13. Configured. The injection mold 2 according to this embodiment rotates the injection mold 2 shown in FIG. 3 clockwise around the central axis P2 of the center pin 4 by (90 ° + (θ / 2)). The arrangement shown in FIG. In the injection mold 2 according to the present embodiment, optimum values for the predetermined dimension (ε) and the predetermined angle (θ) are determined according to the size of the cavity 7 and the type of the resin material containing the reinforcing fiber. .

The rotation driving means 24 for rotating the outer piece 3 by a predetermined angle (θ) is reciprocated between the slider 36 housed so as to be slidable in the slider guide hole 35 formed in the second mold 6 and the slider 36. And an actuator 37 (hydraulic cylinder, pneumatic cylinder, etc.) to be moved. The slider 36 has a drive protrusion 25 that engages with the notch groove 26 of the flange portion 21 of the outer piece 3, and the drive protrusion 25 is hooked on the groove wall of the notch groove 26 of the outer piece 3 to slide the slider guide. The outer piece 3 is rotated around the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ) by sliding in the hole 35. The slider guide hole 35 is communicated with the flange housing recess 28 by a window 38 that allows the drive protrusion 25 to move. The slider 36 is fixed to a rod 40 extending from the actuator 37 and moves together with the rod 40. Further, the slider 36 and the slider guide hole 35 have a quadrangular cross-sectional shape cut along a virtual plane parallel to the YZ coordinate plane, so that the force acting on the slider 36 can be received by the surface. ing.

As shown in FIGS. 1 and 3, the injection mold 2 as described above is configured such that the center 18 a of the cavity forming hole 18 of the outer piece 3 is displaced with respect to the center axis P <b> 2 of the center pin 4 and the cavity width ( The first mold 5 is in an injection standby state in which the positions of the maximum value (Wmax) and the minimum value (Wmin) of W) are on a straight line (center line 33) connecting the center of the center pin 4 and the center of the gate 13. In a state where the second mold 6 is abutted against and the mold is clamped, molten resin containing reinforcing fibers is injected from the gate 13 into the cavity 7. At this time, the molten resin containing reinforcing fibers injected into the cavity 7 has a minimum value (Wmin) of the cavity width (W) (a part of the cavity 7) to a maximum value (Wmax) of the cavity width (W). The inside of the cavity 7 flows evenly toward the part, joins at the part of the maximum value (Wmax) of the cavity width (W), and a weld line 34 is formed at the joining part (see FIG. 4). The injection mold 2 is filled with a molten resin containing reinforcing fibers throughout the cavity 7, and the rotation driving means 24 is operated before the molten resin containing reinforcing fibers cools and loses fluidity. Thus, the outer piece 3 is rotated around the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ) in the clockwise direction by the rotation driving means 24 (see FIG. 2). Thereby, in the injection mold 2, the center axis P 2 of the center pin 4 and the center 18 a of the cavity forming hole 18 of the outer piece 3 coincide with each other, and the cavity width (W) of the cavity 7 is in the circumferential direction of the center pin 4. It becomes constant along. Thus, when the injection mold 2 changes from the state shown in FIG. 1 to the state shown in FIG. 2, the distance between the inner peripheral surface 3 a of the outer piece 3 and the outer peripheral surface 14 a of the large-diameter portion 14 of the center pin 4. Changes, the cavity width (W) of the cavity 7 varies, and the molten resin containing reinforcing fibers in the cavity 7 is forced to flow in the cavity 7. In the molten resin containing reinforcing fibers in the cavity 7, the orientation of the reinforcing fibers is disturbed, and the weld line 34 and surrounding reinforcing fibers are intertwined (see FIG. 4). In particular, the injection mold 2 according to the present embodiment is formed such that the cavity width (W) of the portion of the cavity 7 where the weld line 34 is formed has a maximum value (Wmax). Since the cavity width (W) on the side where the gate 13 is opened becomes the minimum value (Wmin), when the state shown in FIG. 1 is changed to the state shown in FIG. The change (ΔW) in the cavity width (W) at the portion where the weld line 34 is formed and the portion where the gate 13 opens is the largest (ΔW = (Wmax + Wmin) / 2−Wmax or ΔW = (Wmax + Wmin) / 2-Wmin). As a result, in the injection mold 2 according to the present embodiment, the molten resin containing reinforcing fibers on the side where the weld line 34 in the cavity 7 is formed and on the side where the gate 13 opens is more than the other part in the cavity 7. It can flow much and can effectively disturb the orientation of the weld line 34 and the reinforcing fibers in the vicinity thereof.

Thereafter, when the molten resin containing the reinforcing fibers in the cavity 7 is cooled and solidified to form the cylindrical product 1, the injection mold 2 is separated from the first mold 5 and the second mold 6 (the mold is opened). ), The eject sleeve 30 pushes the cylindrical product 1 in the cavity 7 out of the cavity 7. As a result, the injection-molded tubular product 1 is taken out from the cavity 7 of the injection mold 2.

In the injection mold 2, after the cylindrical product 1 is taken out from the cavity 7, the rotation driving means 24 is operated, and the outer piece 3 is rotationally driven from the position shown in FIG. 2 to the injection standby position in FIG. 1. It is rotated back by the means 24 to prepare for the next injection molding.

According to the injection mold 2 according to the present embodiment as described above, the direction of the weld line 34 and the reinforcing fibers near the weld line 34 in the injection-molded tubular product 1 is disturbed, and the weld of the tubular product 1 is disturbed. Since the reinforcing fibers in the vicinity of the line 34 and the weld line 34 are entangled with each other, the weld line 34 of the tubular product 1 is less noticeable and the strength of the portion of the tubular product 1 where the weld line 34 is formed is improved.

(Cylindrical injection molding method)
Below, the injection molding method of the cylindrical article 1 using the injection mold 2 which concerns on this embodiment is demonstrated.

The injection molding method of the tubular product 1 according to the present embodiment includes first to fourth steps that will be described in detail below.

First, in the first step of injection molding, as shown in FIGS. 1 and 3, the center 18a of the cavity forming hole 18 of the outer piece 3 is shifted with respect to the center axis P2 of the center pin 4, and the cavity width (W ) Are on the straight line (center line 33) connecting the center axis P2 of the center pin 4 and the center of the gate 13, and the first mold 5 and the second value (Wmax). In an injection standby state in which the mold 6 is abutted and clamped, molten resin containing reinforcing fibers is injected from the gate 13 into the cavity 7. At this time, the molten resin containing reinforcing fibers injected into the cavity 7 from the gate 13 where the cavity width (W) is at the minimum value (Wmin) is rotated 180 ° from the gate 13 in the circumferential direction (cavity width). (W) is merged at the maximum value (Wmax)), and a weld line 34 is formed at the portion where the molten resin containing the reinforcing fibers merges (see FIG. 4).

Next, in the second step of the injection molding, the molten resin containing the reinforcing fiber is filled in the entire area of the cavity 7, and before the molten resin containing the reinforcing fiber filled in the cavity 7 is cooled and loses fluidity, The outer piece 3 is rotated about the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ) clockwise by the rotation driving means 24, and the central axis P2 of the center pin 4 and the cavity of the outer piece 3 are rotated. The center 18a of the formation hole 18 is made to coincide, and the cavity width (W) of the cavity 7 is made constant along the circumferential direction of the center pin 4 (see FIG. 2). According to the second step of the injection molding, the distance between the inner peripheral surface 3a of the outer piece 3 and the outer surface 14a of the large diameter portion 14 of the center pin 4 changes, and the cavity width (W) of the cavity 7 changes. Thus, the molten resin containing reinforcing fibers in the cavity 7 is forced to flow in the cavity 7. In the molten resin containing reinforcing fibers in the cavity 7, the orientation of the reinforcing fibers is disturbed, and the weld line 34 and surrounding reinforcing fibers are intertwined (see FIG. 4).

Next, in the third step of the injection molding, after the molten resin containing the reinforcing fibers in the cavity 7 is cooled and solidified, the first mold 5 and the second mold 6 are separated, thereby the second mold. The cylindrical product (injection molded product) 1 in the cavity 7 on the 6 side is separated from the gate 13 on the first mold 5 side, and the separation trace 41 of the gate 13 is outside the hollow disc portion 10 of the cylindrical product 1. It is designed to be formed on the surface.

Next, in the fourth step of injection molding, the cylindrical product 1 in the cavity 7 is pushed out of the cavity 7 by the eject sleeve 30, whereby the injection-molded cylindrical product 1 is taken out from the cavity 7.

According to the injection molding method according to the present embodiment as described above, the direction of the weld line 34 and the reinforcing fibers in the vicinity of the weld line 34 in the injection-molded tubular product 1 is disturbed, and the weld line 34 of the tubular product 1 is disturbed. In addition, since the reinforcing fibers in the vicinity of the weld line 34 are entangled, the weld line 34 of the tubular product 1 is less noticeable and the strength of the portion of the tubular product 1 where the weld line 34 is formed is improved.

(Cylindrical product)
A cylindrical product 1 according to this embodiment shown in FIG. 4 is formed by the above-described injection molding method using the above-described injection mold 2. The cylindrical product 1 has a cylindrical portion 8 and a hollow disc portion 10 formed integrally with one end side of the cylindrical portion 8. Further, a separation mark 41 of the gate 13 is formed in the hollow disc portion 10 on one end side of the cylindrical product 1. The tubular product 1 is intricately intertwined with the weld line 34 and the reinforcing fibers 25 in the vicinity of the weld line 34.

In the tubular product 1 according to the present embodiment, the weld line 34 and the direction of the reinforcing fiber in the vicinity of the weld line 34 are disturbed, and the weld line 34 and the reinforcing fiber in the vicinity of the weld line 34 are intertwined. It becomes inconspicuous and the strength of the portion where the weld line 34 is formed is improved.

[Second Embodiment]
(Cylindrical injection mold)
5 to 6 are views showing an injection mold 2 according to the second embodiment of the present invention, and showing a modification of the rotation driving means 24 of the injection mold 2 according to the first embodiment. is there. Among these, FIG. 5 is a diagram showing the structure of the injection mold 2 in the injection standby state. FIG. 6 is a view showing the structure of the injection mold 2 when the outer piece 3 in the injection standby state is eccentrically rotated by a predetermined angle (θ) in the clockwise direction with respect to the center pin 4. FIG. 5 (a) is a plan view of a second mold shown by cutting the injection mold shown in FIG. 5 (b) along the line A6-A6. FIG. 5B is a cross-sectional view of the injection mold shown cut along line A7-A7 in FIG. FIG. 6A is a plan view of the second mold shown by cutting the injection mold shown in FIG. 6B along the line A8-A8. FIG. 6B is a cross-sectional view of the injection mold shown cut along the line A9-A9 in FIG.

The injection mold 2 according to this embodiment shown in FIGS. 5 to 6 has the same configuration as the injection mold 2 according to the first embodiment except for the rotational drive means 42, and therefore the first embodiment. The description which overlaps with the description of the injection mold 2 according to the above will be omitted, and the components (rotation drive means) different from the injection mold 2 according to the first embodiment will be described in detail.

The rotation driving means 42 of the injection mold 2 according to this embodiment includes a slider 44 accommodated in a slider guide hole 43 formed in the second mold 6 so as to be slidable, and the slider 44 in one direction. A spring 45 (compression coil spring) that is always biased, an operation pin 46 that slides the slider 44 biased by the spring 45, and a drive mechanism that slides the operation pin 46 along the operation pin guide hole 47 Part 48.

The slider 44 has a rod part 50 having a quadrangular cross-section cut by a virtual plane parallel to the YZ coordinate plane, and a head part 51 integrally formed at the tip of the rod part 50. The rod portion 50 has a drive protrusion 25 that engages with the notch groove 26 of the flange portion 21 of the outer piece 3, and the drive protrusion 25 is hooked on the groove wall of the notch groove 26 of the outer piece 3 to slide the slider 50. By sliding and moving in the guide hole 43, the outer piece 3 is rotated around the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ). The drive protrusion 25 can move in a window 38 that communicates between the slider guide hole 43 and the flange housing recess 28. The head portion 51 is formed so as to protrude from the rod portion 50 by the same dimension along the + Y axis direction and the −Y axis direction, and is formed so as to protrude from the rod portion 50 along the + Z axis direction. The cross-sectional shape cut along a virtual plane parallel to the YZ coordinate plane is a quadrangle. Further, as shown in FIG. 5B, the head portion 51 is formed with an inclined surface 52 that is inclined from the tip (tip along the + X axis direction) obliquely downward to the left. By being pushed by 46, a slope component force that resists the biasing force of the spring 45 is generated.

The operation pin 46 is a rod-like body having a quadrangular cross section cut along a virtual plane parallel to the XY coordinate plane, and is connected to a drive mechanism unit 48 driven by a drive device (not shown) of the eject sleeve 30. Has been. The operation pin 46 can be slid by the drive mechanism 48 in an operation pin guide hole 47 extending along the Z-axis direction. Further, as shown in FIG. 5B, the operation pin 46 is formed with an inclined surface 53 that is inclined obliquely downward from the tip (upper end) to the left and this inclined surface 53 is an inclined surface of the slider 44. The slider 44 is brought into sliding contact with the surface 52. The operation pin 46 is formed to have the same width dimension (λ) as the width dimension (λ) of the head portion 51 of the slider 44 (see FIG. 5A). The operation pin 46 is slid by the drive mechanism 48 separately from the eject sleeve 30.

The slider guide hole 43 is formed along the X-axis direction, and a rod portion guide hole 54 that guides the sliding movement of the rod portion 50 of the slider 44 and a head portion that guides the sliding movement of the head portion 51 of the slider 44. And a guide hole 55. In the slider guide hole 43, the head portion guide hole 55 opens into the operation pin guide hole 47. The rod guide hole 54 of the slider guide hole 43 has a square shape that is the same as the cross-sectional shape of the rod portion 50 of the slider 44 in a cross-section taken along a virtual plane parallel to the YZ coordinate plane. The slider 44 is slid along the X-axis direction without making surface contact with the portion 50 and changing the posture of the slider 44. Further, the head portion guide hole 55 of the slider guide hole 43 has a quadrangular shape similar to the cross sectional shape of the head portion 51 of the slider 44 in a sectional shape cut along a virtual plane parallel to the YZ coordinate plane. The slider 44 is slid along the X-axis direction without changing the posture of the slider 44 in surface contact with the head portion 51. As a result, the slider guide hole 43 accurately engages the drive protrusion 25 of the slider 44 with the notch groove 26 of the flange portion 21 of the outer piece 3, and the inclined surface 52 at the tip of the slider 44 is inclined to the operation pin 46. The outer piece 3 can be accurately rotated by a predetermined angle (θ) while being brought into surface contact with the surface 53 accurately.

The operation pin guide hole 47 is formed along the Z-axis direction and intersects the slider guide hole 43 at a right angle. The operation pin guide hole 47 has a quadrangular shape similar to that of the operation pin 46 in a cross-sectional shape cut along a virtual plane parallel to the XY coordinate plane, so that the head portion 51 of the slider 44 can enter. (See FIG. 5). The wall surface 56 of the operation pin guide hole 47 facing the slider guide hole 43 is abutted against the front end surface 57 of the head portion 51 of the slider 44 biased by the spring 45, and in the injection standby state. It functions as a positioning surface for the slider 44 (see FIG. 5). The operation pin guide hole 47 can accommodate the operation pin 46 at a position where it does not contact the slider 44 in the injection standby state. Such an operation pin guide hole 47 is in surface contact with the operation pin 46 and slides the operation pin 46 along the Z-axis direction without changing the posture of the operation pin 46. As a result, the operation pin guide hole 47 accurately brings the inclined surface 53 of the operation pin 46 into surface contact with the inclined surface 52 of the head portion 51 of the slider 44, and accurately rotates the outer piece 3 by a predetermined angle (θ). be able to.

At the position facing the operation pin guide hole 47 of the mold matching surface 5 a of the first mold 5, a bottomed shape that enables the tip side of the operation pin 46 to protrude from the mold matching surface 6 a of the second mold 6. The operation pin relief hole 58 is formed. As a result, the operation pin 46 that slides in the operation pin guide hole 47 causes the tip to enter the operation pin relief hole 58 in a state where the first mold 5 and the second mold 6 are clamped, and the slider 44 can be pushed into the slider guide hole 43 against the biasing force of the spring 45, and the tip of the head portion 51 of the slider 44 can be positioned by the side surface 60 facing the slider 44. As a result, the operation pin 46 can position the slider 44 at a position where the outer piece 3 is rotated clockwise from the position in the injection standby state by a predetermined angle (θ), and the slider 44 biased by the spring 45. Can be stopped.

In the injection mold 2 according to this embodiment as described above, the outer piece 3 is rotated by the rotation driving means 42 in the same manner as the injection mold 2 according to the first embodiment. That is, in the injection mold 2 according to the present embodiment, as shown in FIGS. 3 and 5, the center 18a of the cavity forming hole 18 of the outer piece 3 is shifted with respect to the center axis P2 of the center pin 4, In the injection standby state where the position of the maximum value (Wmax) and the minimum value (Wmin) of the cavity width (W) is on a straight line (center line 33) connecting the center axis P2 of the center pin 4 and the center of the gate 13, and In a state where the first mold 5 and the second mold 6 are abutted and clamped, molten resin containing reinforcing fibers is injected into the cavity 7 from the gate 13. At this time, the molten resin containing reinforcing fibers injected into the cavity 7 is evenly distributed from the minimum value (Wmin) portion of the cavity width (W) toward the maximum value (Wmax) of the cavity width (W). It flows and merges at the maximum value (Wmax) of the cavity width (W), and a weld line 34 is formed at the merged portion (see FIG. 4). The injection mold 2 is filled with a molten resin containing reinforcing fibers throughout the cavity 7, and the rotation driving means 42 is operated before the molten resin containing reinforcing fibers cools and loses its fluidity. Thus, the outer piece 3 is rotated around the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ) in the clockwise direction by the rotation driving means 42 (see FIG. 6). Thereby, in the injection mold 2, the center axis P 2 of the center pin 4 and the center 18 a of the cavity forming hole 18 of the outer piece 3 coincide with each other, and the cavity width (W) of the cavity 7 is in the circumferential direction of the center pin 4. It becomes constant along. Thus, when the injection mold 2 changes from the state shown in FIG. 5 to the state shown in FIG. 6, the inner peripheral surface 3 a of the outer piece 3 and the outer surface 14 a of the large-diameter portion 14 of the center pin 4 change. The cavity width (W) of the cavity 7 changes, and the molten resin containing reinforcing fibers in the cavity 7 is forced to flow in the cavity 7. In the molten resin containing reinforcing fibers in the cavity 7, the orientation of the reinforcing fibers is disturbed, and the weld line 34 and surrounding reinforcing fibers are intertwined (see FIG. 4).

As described above, the injection mold 2 according to the present embodiment operates in the same manner as the injection mold 2 according to the first embodiment, and has the same effect as the injection mold 2 according to the first embodiment. Obtainable.

In addition, the injection molding method using the injection mold 2 according to this embodiment includes the same first to fourth steps as the injection molding method according to the first embodiment. The same effects as those of the injection molding method can be obtained.

Moreover, the cylindrical product 1 injection-molded using the injection mold 2 according to the present embodiment is the same as the cylindrical product 1 injection-molded using the injection mold 2 according to the first embodiment. Similarly, the direction of the reinforcing fiber in the vicinity of the weld line 34 and the weld line 34 is disturbed, and the reinforcing fiber in the vicinity of the weld line 34 and the weld line 34 is entangled, so that the weld line 34 becomes difficult to stand out and the weld line 34 is formed. The strength of the part is improved.

[Third Embodiment]
7 to 8 are views showing an injection mold 2 of the tubular product 1 according to the third embodiment of the present invention. Among these, FIG. 7 is a figure which shows the modification of the injection mold 2 which concerns on 1st Embodiment, and is a figure which shows the structure of the injection mold 2 in an injection standby state. FIG. 8 is a view showing the structure of the injection mold 2 when the outer piece 3 in the injection standby state is eccentrically rotated by a predetermined angle (θ) in the clockwise direction with respect to the center pin 4. FIG. 7A is a plan view of the second mold shown by cutting the injection mold shown in FIG. 7B along the line A10-A10. FIG. 7B is a cross-sectional view of the injection mold shown cut along the line A11-A11 in FIG. FIG. 8A is a plan view of the second mold shown by cutting the injection mold shown in FIG. 8B along the line A12-A12. FIG. 8B is a cross-sectional view of the injection mold shown cut along the line A13-A13 in FIG.

The injection mold 2 according to this embodiment is different from the injection mold 2 according to the first embodiment in the shape of the cavity 7 and the position of the gate 13, but the other basic configuration is related to the first embodiment. Since it is the same as the injection mold 2, the same reference numerals as those of the injection mold 2 according to the first embodiment are attached to the components corresponding to the injection mold 2 according to the first embodiment, and the first embodiment. The description overlapping with the description of is omitted.

As shown in FIGS. 7 to 8, in the injection mold 2, the cylindrical product 1 to be injection-molded has a cylindrical shape, and the cylindrical product 1 does not include the hollow disc portion 10 (FIGS. 4 and 4). 9), the second cavity portion 12 of the injection mold 2 according to the first embodiment is not provided, and the cavity 7 corresponds to the first cavity portion 11 of the injection mold 2 according to the first embodiment. It consists only of parts to do. Further, the center pin 4 is formed with the same outer diameter dimension (formed only by the large diameter portion 14), and the front end surface 17 is abutted against the abutting surface 5a of the first mold 5, and is formed in a round bar shape. This is different from the center pin 4 of the injection mold 2 according to the first embodiment in that the small diameter portion 15 is omitted. The gate 13 is formed in the first mold 5 so as to open to one end side of the cavity 7. In addition, the injection mold 2 according to the present embodiment, like the injection mold 2 according to the first embodiment, in the injection standby state, the gate 13 is positioned at the minimum value (Wmin) of the cavity width (W). The molten resin containing reinforcing fibers injected into the cavity 7 from the gate 13 is configured to merge at a position where the cavity width (W) of the cavity 7 is the maximum value (Wmax) (FIG. 3). reference).

In the injection mold 2 according to the present embodiment, the center 18a of the cavity forming hole 18 of the outer piece 3 is shifted with respect to the center axis P2 of the center pin 4 in the same manner as the injection mold 2 according to the first embodiment. In such a state (see FIGS. 7 (a) and 3), the first mold 5 and the second mold 6 are brought into contact with each other and clamped (see FIG. 7 (b)), and a molten resin containing reinforcing fibers. Is injected from the gate 13 into the cavity 7. At this time, a weld line 34 is formed at the joining portion of the molten resin containing reinforcing fibers in the cavity 7. The injection mold 2 is filled with a molten resin containing reinforcing fibers throughout the cavity 7, and the rotation driving means 24 is operated before the molten resin containing reinforcing fibers cools and loses fluidity. Thus, the outer piece 3 is rotated about the central axis P1 of the eccentric rotation support portion 23 by a predetermined angle (θ) in the clockwise direction by the rotation driving means 24, and the center 18a of the cavity forming hole 18 of the outer piece 3 is rotated. Is aligned with the central axis P2 of the center pin 4 (see FIG. 8). Thereby, in the injection mold 2, the distance between the inner peripheral surface 3 a of the outer piece 3 and the outer peripheral surface 14 a of the center pin 4 is changed, and the molten resin containing reinforcing fibers in the cavity 7 is forced inside the cavity 7. Fluidized. As a result, the molten resin containing the reinforcing fibers in the cavity 7 is disturbed in the orientation of the reinforcing fibers, and the weld line 34 and the surrounding reinforcing fibers are intertwined.

The injection molding method according to this embodiment is the same as the injection molding method according to the first embodiment, although the injection mold 2 to be used is slightly different from the injection molding die 2 according to the first embodiment. is there. Therefore, according to the injection molding method according to the present embodiment, the same effects as those of the injection molding method according to the first embodiment can be obtained.

FIG. 9 is a view showing a cylindrical product 1 injection-molded by the injection mold 2 according to this embodiment. 9 (a) is a front view of the tubular product 1, FIG. 9 (b) is a side view of the tubular product 1, and FIG. 9 (c) is a line A14-A14 in FIG. 9 (a). It is sectional drawing of the cylindrical article 1 cut | disconnected and shown along.

As shown in FIG. 9, a separation mark 41 of the gate 13 is formed on the end surface 61 on the one end side of the tubular product 1. The cylindrical product 1 is intricately intertwined with the weld line 34 and the reinforcing fibers in the vicinity of the weld line 34.

The cylindrical product 1 according to the present embodiment, like the cylindrical product 1 according to the first embodiment, is disturbed in the direction of the weld line 34 and the reinforcing fibers in the vicinity of the weld line 34, so that the weld line 34 and the weld line 34 are welded. Since the reinforcing fibers in the vicinity of the line 34 are intertwined, the weld line 34 becomes difficult to stand out, and the strength of the portion where the weld line 34 is formed is improved.

[Fourth Embodiment]
FIGS. 10 to 11 are views showing an injection mold 2 according to the fourth embodiment of the present invention, and showing a modification of the rotation driving means 24 of the injection mold 2 according to the third embodiment. is there. Among these, FIG. 10 is a diagram showing the structure of the injection mold 2 in the injection standby state. FIG. 11 is a view showing the structure of the injection mold 2 when the outer piece 3 in the injection standby state is eccentrically rotated by a predetermined angle (θ) in the clockwise direction with respect to the center pin 4. FIG. 10A is a plan view of a second mold shown by cutting the injection mold shown in FIG. 10B along the line A15-A15. FIG. 10B is a cross-sectional view of the injection mold shown cut along the line A16-A16 in FIG. FIG. 11 (a) is a plan view of a second mold shown by cutting the injection mold shown in FIG. 11 (b) along the line A17-A17. FIG. 11B is a cross-sectional view of the injection mold shown cut along line A18-A18 in FIG.

The injection mold 2 according to the present embodiment is obtained by replacing the rotation drive means 24 of the injection mold 2 according to the third embodiment with the rotation drive means 42 according to the second embodiment. It is used for injection molding the same cylindrical product 1 (cylindrical product 1 shown in FIG. 9) as the injection mold 2 according to the above.

The cylindrical product 1 injection-molded using the injection mold 2 according to the present embodiment is the cylindrical product 1 injection-molded using the injection mold 2 according to the third embodiment. In the same manner, the orientation of the weld line 34 and the reinforcement fiber in the vicinity of the weld line 34 is disturbed and the reinforcement fiber in the vicinity of the weld line 34 and the weld line 34 is entangled, so that the weld line 34 becomes difficult to stand out and the weld line 34 is formed. The strength of the applied portion is improved.

[Fifth Embodiment]
(Cylindrical injection mold)
FIG. 12 is a view showing an injection mold 2 of the tubular product 1 according to the fifth embodiment of the present invention. The injection mold 2 according to the present embodiment shown in FIG. 12 is used for injection molding the tubular product 1 shown in FIG. 4, and the injection mold according to the first or second embodiment is used. Same as type 2. FIG. 12A is a plan view (plan view of the second mold 104) in which the first mold 103 of the injection mold 2 shown in FIG. FIG. 6 is a view showing a state (injection standby state) in which the center 162a of the slider 162 is shifted from the center 150a of the center pin 150 by a predetermined dimension (ε). 12B is a plan view of the second mold 104, and shows a state in which the center 162a of the slider 162 of the outer piece 151 and the center 150a of the center pin 150 are made to coincide. FIG. 12C is a cross-sectional view of the injection mold 2 cut along the line A19-A19 in FIG.

In the injection mold 2 according to this embodiment shown in FIG. 12, a cavity 105 is formed on the side of the butted

surfaces

103 a and 104 a of the first mold 103 and the second mold 104. The cavity 105 has a shape that forms the cylindrical product 1 shown in FIG. 4 and is filled with molten resin containing reinforcing fibers. As shown in FIG. 4, the tubular product 1 includes a cylindrical portion 8 and a hollow disc portion 10 that is integrally formed on one end side of the cylindrical portion 8. The cavity 105 that forms the cylindrical product 1 includes a first cavity part 108 that forms the cylindrical part 8, and a second cavity part 110 that is located on one end side of the first cavity part 108 and forms the hollow disk part 10. ,have. The cavity 105 is formed in the second mold 104 so that the opening end is closed by the first mold 103.

The first mold 103 is formed with a gate 111 (pinpoint gate) that opens to the second cavity portion 110 formed in the second mold 104. In FIG. 12A, the gate 111 is formed in the first mold 103 so as to be located on a center line 174 that passes through the center 150a of the center pin 150 and extends in the X-axis direction. The second mold 104 includes a center pin 150 positioned on the inner peripheral surface side of the first cavity portion 108 and an outer piece 151 positioned on the outer peripheral surface side of the first cavity portion 108. The outer peripheral surface of the center pin 150 forms the inner peripheral surface side of the first cavity portion 108, and the inner peripheral surface of the cavity forming hole 168 of the outer piece 151 forms the outer peripheral surface side of the first cavity portion 108. Yes. The second mold 104 includes a second mold main body 152, an outer piece support mold portion 153 arranged to overlap the second mold main body portion 152, and the outer piece support mold portion 153. And an outer piece presser mold part 154 arranged in an overlapping manner.

The center pin 150 is a cylindrical portion formed integrally with the tip of the shaft portion 156 of the inner mold 155, and constitutes the inner mold 155 together with the shaft portion 156. On the front end surface 157 of the center pin 150, a round bar-like protrusion 158 that is abutted against the abutting surface 103a of the first mold 103 is formed. This protrusion 158 is integrally formed at the center of the front end surface 157 of the center pin 150, and forms the central hole 16 of the hollow disk portion 10 of the tubular product 1 (see FIG. 4). An eject sleeve 160 is fitted on the outer periphery of the shaft portion 156 of the inner mold 155 so as to be slidable.

The outer piece 151 is accommodated in the second mold 104 so as to be slidable, and slides along a plane perpendicular to the central axis 161 of the center pin 150 (the surface 152a of the second mold main body 152). The outer piece 151 includes a cylindrical slider 162, an operation rod 165 that is integrally formed on the outer peripheral side of the slider 162 and slidingly contacts the outer peripheral surface (cam surface) 164 of the cam 163, and the outer peripheral side of the slider 162. And a spring receiving rod 167 that presses the operating rod 165 against the outer peripheral surface 164 of the cam 163 by the elastic force of the spring 166.

The slider 162 is formed with a round hole-shaped cavity forming hole 168 in the central portion, and the shape in plan view is a two-sided width shape as if both sides of the cylindrical body are cut off, passing through the center 162a and on the Y axis. It is formed in a line-symmetric shape with respect to the center line 170 extending along the line (see FIG. 12A). On both sides of the slider 162 in the width direction (the direction along the X axis), slide surfaces 171 extending along the Y axis direction are formed. The slider 162 is accommodated in an outer piece guide hole 172 formed in the outer piece support die portion 153 and the outer piece holding die portion 154, and the slide surface 171 is a slide guide surface 173 of the outer piece guide hole 172. Can be slid along. Here, the outer piece guide hole 172 of the outer piece supporting mold part 153 and the outer piece guide hole 172 of the outer piece holding mold part 154 have the same shape, and the shape in plan view is a rectangular shape. The outer piece guide hole 172 is formed in a line-symmetric shape with respect to a center line 174 that passes through the center 150a of the center pin 150 and extends along the X-axis direction, and passes through the center 150a of the center pin 150. It is formed in a line-symmetric shape with respect to a center line 170 extending along the Y-axis direction. Further, the outer piece guide hole 172 contacts the slider 162 when the center 162a of the slider 162 (center of the cavity forming hole 168) slides by a predetermined dimension (ε) from the position where it matches the center 150a of the center pin 150. It is formed with dimensions that do not touch. The lift amount (ε) of the cam 163 and the movement amount (ε) of the slider 162 are optimum values according to the thickness of the cylindrical portion 8 of the tubular product 1 and the difference in the material of the molten resin containing reinforcing fibers. Is determined.

The operation rod 165 is formed on one end side of the slider 162 along the Y-axis direction, and a cam contact surface 165b is formed by rounding the tip of a round rod-shaped rod body 165a extending along the Y-axis direction into a spherical shape. ing. The operation rod 165 is fitted so as to be slidable into a first rod hole 175 formed on the overlapping surface side of the outer piece supporting die portion 153 and the outer piece holding die portion 154, and the distal end side is the outer piece. It protrudes into a cam accommodation hole 176 formed in the support mold part 153 and the outer piece presser mold part 154, and the cam contact surface 165 b comes into contact with the outer peripheral surface (cam surface) 164 of the cam 163.

The spring receiving rod 167 is formed on the other end side along the Y-axis direction of the slider 162, and extends in a direction opposite to the direction in which the operation rod 165 extends. The spring receiving rod 167 has a round bar-like small-diameter spring support rod portion 167a inserted into a space on the inner diameter side of a spring (compression coil spring) 166 and a round bar-like large diameter (spring support) with which one end side of the spring 166 abuts. A spring seat portion 167b having a larger diameter than the rod portion 167a. The spring seat 167b of the spring receiving rod 167 is fitted so as to be slidable into the second rod hole 177 formed on the overlapping surface side of the outer piece supporting die portion 153 and the outer piece holding die portion 154. Are combined. Further, the spring support rod portion 167a is fitted so that the tip side can slide and move into a third rod hole 178 formed on the overlapping surface side of the outer piece support die portion 153 and the outer piece holding die portion 154. ing. Here, the spring 166 is accommodated in a spring accommodating chamber 180 formed on the overlapping surface side of the outer piece supporting die portion 153 and the outer piece holding die portion 154. The spring accommodating chamber 180 is a round hole-shaped space having an inner diameter larger than the outer diameter of the spring seat portion 167b and the outer diameter of the spring 166, and is accommodated in a state where the spring 166 is compressed. . The spring 166 has one end in the height direction in contact with the spring seat 167b and the other end in the height direction contacts the end surface 180a on the other end side (the third rod hole 178 side) of the spring accommodating chamber 180. The operating rod 165 is always pressed against the outer peripheral surface (cam surface) 164 of the cam 163.

The cam 163 is accommodated in a cam accommodating chamber 176 formed in the outer piece support die portion 153 and the outer piece presser die portion 154 so that the cam shaft 181 rotates around the second die body portion 152. It is supported movably. The cam 163 is configured such that the cam shaft 181 is rotated by a rotation driving means 135 (for example, a rotation driving means including a stepping motor and a plurality of gears), whereby the outer piece 151 is moved by a lift amount (ε). It can be slid along the direction. As a result, the outer piece 151 has a position where the center 162a of the slider 162 (center of the cavity forming hole 168) is shifted from the center 150a of the center pin 150 by a predetermined dimension (ε) (position shown in FIG. 12A). The slider 162 slides between a position (a position shown in FIG. 12B) where the center 162a of the slider 162 (the center of the cavity forming hole 168) coincides with the center 150a of the center pin 150.

In the injection mold 2 as described above, molten resin containing reinforcing fibers is injected from the gate 111 into the cavity 105 in a state where the first mold 103 and the second mold 104 are abutted and clamped. . At this time, the outer piece 151 is held at a position shifted from the center pin 150 by a predetermined dimension (ε), as shown in FIG. At this time, a weld line 34 is formed in the joining portion of the molten resin containing reinforcing fibers in the cavity 105 (see FIG. 4). Here, the joining portion of the molten resin containing reinforcing fibers in the cavity 105 is located on the center line 174 rotated 180 ° around the center 150 a of the center pin 150 from the opening position of the gate 111. Then, the entire area in the cavity 105 is filled with molten resin containing reinforcing fibers, and before the molten resin containing reinforcing fibers cools and loses its fluidity, the rotation driving means 135 is operated to drive the cam 163 to rotate. When the means 135 is rotated by a predetermined angle (180 °), the outer piece 151 is moved to the spring 166 until the center 162a (center of the cavity forming hole 168) of the slider 162 of the outer piece 151 and the center 150a of the center pin 150 coincide. And slide to move (see FIG. 12B). Thereby, in the injection mold 2, the distance between the outer peripheral surface of the center pin 150 and the inner peripheral surface of the cavity forming hole 18 is changed, the cavity width (W) is changed, and the molten fiber containing reinforcing fibers in the cavity 105 is melted. The resin is forced to flow in the cavity 105. As a result, in the molten resin containing reinforcing fibers in the cavity 105, the orientation of the reinforcing fibers is disturbed, and the weld line 34 and the surrounding reinforcing fibers are intertwined (see FIG. 4).

Thereafter, when the molten resin containing reinforcing fibers in the cavity 105 is cooled and solidified to form the cylindrical product 1, the injection mold 2 is separated from the first mold 103 and the second mold 104 (the mold is opened). ), The eject sleeve 160 pushes the cylindrical product 1 in the cavity 105 out of the cavity 105. As a result, the injection-molded tubular product 1 is taken out from the cavity 105 of the injection mold 2.

In the injection mold 2, after the cylindrical product 1 is taken out from the cavity 105, the rotation driving means 135 is operated, and when the cam 163 is rotated by the rotation driving means 135, the spring 166 moves the cam 163. The pressed outer piece 151 is returned from the position shown in FIG. 12B to the initial position shown in FIG. 12A (the position in the injection standby state) to prepare for the next injection molding.

As shown in FIGS. 12A and 12C, the injection mold 2 has the outer pin 151 of the second mold 104 (the center 162a of the slider 162 and the center of the cavity forming hole 168) as a center pin. 150 (center 150a of the center pin 150) is held in a state shifted by a predetermined dimension (ε) (injection standby state), and the first mold 103 and the second mold 104 are abutted and clamped. Thereafter, molten resin containing reinforcing fibers is injected from the gate 111 into the cavity 105 (first step of injection molding). At this time, the molten resin injected into the cavity 105 from the gate 111 merges at a position rotated 180 ° in the circumferential direction from the gate 111, and a weld line 34 is formed at a portion where the molten resin containing reinforcing fibers merges. (See FIG. 4).

In the injection mold 2, the cam 163 is rotationally driven before the molten resin containing reinforcing fibers is filled in the entire area of the cavity 105 and the fluidity of the molten resin containing reinforcing fibers filled in the cavity 105 is impaired. The outer piece 151 is rotated by a predetermined angle (θ) by means 135, and the outer piece 151 is slid from the position shown in FIG. 12A to the position shown in FIG. 12B, and the center 162 a (cavity) of the slider 162 of the outer piece 151. The center of the formation hole 168 and the center 150a of the center pin 150 coincide (second step of injection molding). At this time, the molten resin containing reinforcing fibers in the cavity 105 is forced to flow in the circumferential direction of the cavity 105 in accordance with a change in the gap formed between the outer piece 151 and the center pin 150. As a result, the molten resin containing the reinforcing fibers in the cavity 105 is disturbed in the fiber orientation of the weld line 34 and its surroundings, and the weld line 34 and its surrounding reinforcing fibers are entangled so that the weld line 34 is hardly noticeable.

In the injection mold 2, after the molten resin containing the reinforcing fibers in the cavity 105 is cooled and solidified, the first mold 103 and the second mold 104 are separated (the mold is opened). At this time, the cylindrical product (injection molded product) 1 in the cavity 105 on the second mold 104 side and the gate 111 on the first mold 103 side are separated, and a separation mark 41 of the gate 111 is formed on the cylindrical product 1. It is formed on the outer surface of the hollow disc portion 10 (third step of injection molding).

Next, the cylindrical product 1 in the cavity 105 is pushed out of the cavity 105 by the eject sleeve 160. Thereby, the injection-molded cylindrical product 1 is taken out from the cavity 105 (fourth step of injection molding).

According to the injection molding method according to the present embodiment as described above, the direction of the weld line 34 and the reinforcing fibers in the vicinity of the weld line 34 in the injection-molded tubular product 1 is disturbed, and the weld line 34 of the tubular product 1 is disturbed. In addition, since the reinforcing fibers in the vicinity of the weld line 34 are entangled, the weld line 34 of the tubular product 1 is less noticeable and the strength of the portion of the tubular product 1 where the weld line 34 is formed is improved (see FIG. 4).

In the injection mold 2 according to the present embodiment, the shape of the cavity 105 is changed in accordance with the shape of the cylindrical product 1 shown in FIG. Similarly to the injection mold 2 according to the fourth embodiment, the cylindrical product 1 shown in FIG. 9 can be injection molded.

[Other Embodiments]
Moreover, the

gates

13 and 111 of the injection mold 2 according to each of the above embodiments can disturb the direction of the weld line 34 and the reinforcing fiber in the vicinity of the weld line 34, and the strength of the weld line 34 of the tubular product 1 can be increased. As long as it can be improved, the opening position to the

cavities

7 and 105 may be shifted.

Further, in the first to second and fifth embodiments, the aspect in which the thickness of the cylindrical portion 8 of the cylindrical product 1 and the thickness of the hollow disc portion 10 are made uniform is illustrated. The thickness of the portion 8 and the thickness of the hollow disc portion 10 may be changed. Moreover, in the said 3rd thru | or 4th embodiment, although the aspect which made the thickness of the cylindrical goods 1 uniform was illustrated, you may change the thickness of the cylindrical goods 1. FIG.

DESCRIPTION OF SYMBOLS 1 ... Cylindrical product, 2 ... Injection mold, 3, 151 ... Outer piece, 4,150 ... Center pin, 7, 105 ... Cavity, 13, 111 ... Gate (pin point gate), 34 …… Weld line

Claims

By injecting molten resin containing reinforcing fibers into the cavity from the gate, the molten resin containing reinforcing fibers merges in the cavity to form a weld line.
The cavity is formed between a center pin that forms the inner peripheral surface side of the cylindrical product and an outer piece that forms the outer peripheral surface side of the cylindrical product,
The outer piece is moved with respect to the center pin, thereby changing the distance to the center pin to forcibly flow the molten resin containing the reinforcing fibers in the cavity, and the weld line Disturb the direction of the reinforcing fiber,
A cylindrical product injection mold characterized by the above.
The outer piece is rotated in an eccentric state with respect to the center axis of the center pin.
The cylindrical product injection mold according to claim 1.
The outer piece is slid along a plane orthogonal to the center axis of the center pin.
The cylindrical product injection mold according to claim 1.
The cavity has a cavity portion that forms a cylindrical portion of the tubular product,
The inner peripheral surface of the cavity portion is formed by the outer peripheral surface of the center pin,
The outer peripheral surface of the cavity portion is formed by the inner peripheral surface of the cavity forming hole of the outer piece,
The center of the cavity forming hole of the outer piece is aligned with the center axis of the center pin from a position shifted from the center axis of the center pin when the outer piece is moved with respect to the center pin. Moved to,
A cylindrical product injection mold according to claim 2 or 3.
The gate can be ejected to a position where the distance between the inner peripheral surface and the outer peripheral surface of the cavity portion is the narrowest at the position where the center of the cavity forming hole is most greatly displaced from the center axis of the center pin. Arranged,
The weld line is formed at a position where the center of the cavity forming hole is most deviated from the center axis of the center pin at a position where the interval between the inner peripheral surface and the outer peripheral surface of the cavity portion is the widest.
The cylindrical product injection mold according to claim 4.
Injecting molten resin containing reinforcing fibers into the cavity from the gate, the molten resin containing reinforcing fibers merges in the cavity to form a weld line.
The cavity is formed between a center pin that forms the inner peripheral surface side of the cylindrical product and an outer piece that forms the outer peripheral surface side of the cylindrical product,
By moving the outer piece with respect to the center pin, the distance between the center pin is changed, the molten resin containing the reinforcing fibers in the cavity is forced to flow, and the reinforcing fibers of the weld line Disturb the direction,
An injection molding method for a cylindrical product characterized by the above.
In the tubular product made of fiber reinforced resin material in which molten resin containing reinforcing fibers is injected from the gate into the cavity, and the molten resin containing reinforcing fibers merges in the cavity to form a weld line,
The cavity is formed between a center pin that forms the inner peripheral surface side of the cylindrical product and an outer piece that forms the outer peripheral surface side of the cylindrical product,
By moving the outer piece relative to the center pin, the distance from the center pin is changed, the molten resin containing the reinforcing fibers in the cavity is forced to flow, and the weld line The direction of the reinforcing fiber was disturbed,
A tubular product made of fiber-reinforced resin material.